Implement billing status notification and enhance user management integration

- Added `NotifyBillingStatusChangedAsync` method to `IRealtimeNotifier` for notifying clients about changes in billing status.
- Updated `BillingConfigResumer` to call the new notification method after modifying billing configurations, ensuring users receive real-time updates.
- Enhanced `ListUsersQueryHandler` to include a `BillingPendingReview` property in `UserSummaryDto`, indicating if a user has a pending payment request awaiting confirmation.
- Refactored various command handlers to utilize `AdvisoryLock` for managing concurrent requests, preventing race conditions in billing operations.
- Updated tests to cover new notification behaviors and ensure proper functionality in billing status management.

backend/tests/PnvPanel.Application.Tests/Admin/Billing/ConfirmPaymentRequestCommandHandlerTests.cs

@@ -220,6 +220,7 @@ public class ConfirmPaymentRequestCommandHandlerTests
                 Arg.Is<DateTimeOffset?>(d => d == activeConfig.ExpiresAt),
                 Arg.Any<CancellationToken>()
             );
+        await _notifier.Received(1).NotifyBillingStatusChangedAsync(userId, Arg.Any<CancellationToken>());
     }
 
     [Fact]

backend/tests/PnvPanel.Application.Tests/Admin/Billing/RejectPaymentRequestCommandHandlerTests.cs

@@ -147,6 +147,8 @@ public class RejectPaymentRequestCommandHandlerTests
                 Arg.Any<DateTimeOffset?>(),
                 Arg.Any<CancellationToken>()
             );
+        // Фронт (/billing) должен узнать о смене статуса сразу, не дожидаясь опроса.
+        await _notifier.Received(1).NotifyBillingStatusChangedAsync(userId, Arg.Any<CancellationToken>());
     }
 
     [Fact]

backend/tests/PnvPanel.Application.Tests/Admin/Support/CloseTicketCommandHandlerTests.cs

@@ -1,6 +1,7 @@
 using NSubstitute;
 using PnvPanel.Application.Admin.Support;
 using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Support;
 using PnvPanel.Application.Tests.TestSupport;
 using PnvPanel.Domain.Support;
 using Xunit;
@@ -65,4 +66,31 @@ public class CloseTicketCommandHandlerTests
         Assert.True(result.IsSuccess);
         Assert.Equal(TicketStatus.Closed, ticket.Status);
     }
+
+    [Fact]
+    public async Task Handle_WhenExtensionRequest_ReturnsOnlyBugReportCanBeClosedDirectly()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var ticket = SupportTicket.CreateExtensionRequest(userId, 30);
+        dbContext.SupportTickets.Add(ticket);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        var currentUser = FakeCurrentUser.Authenticated(Guid.NewGuid(), "admin");
+        var handler = new CloseTicketCommandHandler(
+            dbContext,
+            _notifier,
+            _telegramNotifier,
+            currentUser
+        );
+
+        var result = await handler.Handle(
+            new CloseTicketCommand(ticket.Id),
+            CancellationToken.None
+        );
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(SupportErrors.OnlyBugReportCanBeClosedDirectly, result.Error);
+        Assert.Equal(TicketStatus.Open, ticket.Status);
+    }
 }

backend/tests/PnvPanel.Application.Tests/Admin/Support/ResolveTicketCommandHandlerTests.cs

@@ -1,6 +1,7 @@
 using NSubstitute;
 using PnvPanel.Application.Admin.Support;
 using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Support;
 using PnvPanel.Application.Tests.TestSupport;
 using PnvPanel.Domain.Support;
 using Xunit;
@@ -65,4 +66,34 @@ public class ResolveTicketCommandHandlerTests
         Assert.True(result.IsSuccess);
         Assert.Equal(TicketStatus.Resolved, ticket.Status);
     }
+
+    [Fact]
+    public async Task Handle_WhenRoleRequest_ReturnsOnlyBugReportCanBeResolvedDirectly()
+    {
+        // Заявку на роль/продление можно решить только через Approve/Reject — Resolve обходил бы
+        // одобрение (роль/продление так и не назначились бы), см. CLAUDE.md.
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var roleId = Guid.NewGuid();
+        var ticket = SupportTicket.CreateRoleRequestForExistingRole(userId, roleId);
+        dbContext.SupportTickets.Add(ticket);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        var currentUser = FakeCurrentUser.Authenticated(Guid.NewGuid(), "admin");
+        var handler = new ResolveTicketCommandHandler(
+            dbContext,
+            _notifier,
+            _telegramNotifier,
+            currentUser
+        );
+
+        var result = await handler.Handle(
+            new ResolveTicketCommand(ticket.Id),
+            CancellationToken.None
+        );
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(SupportErrors.OnlyBugReportCanBeResolvedDirectly, result.Error);
+        Assert.Equal(TicketStatus.Open, ticket.Status);
+    }
 }

backend/tests/PnvPanel.Application.Tests/Admin/Users/ListUsersQueryHandlerTests.cs

@@ -0,0 +1,81 @@
+using NSubstitute;
+using PnvPanel.Application.Admin.Users;
+using PnvPanel.Application.Common.Interfaces;
+using PnvPanel.Application.Common.Models;
+using PnvPanel.Application.Tests.TestSupport;
+using PnvPanel.Domain.Billing;
+using Xunit;
+
+namespace PnvPanel.Application.Tests.Admin.Users;
+
+public class ListUsersQueryHandlerTests
+{
+    private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();
+
+    private static UserSummaryDto Summary(Guid id) =>
+        new(id, "alice", "premium", true, false, DateTimeOffset.UtcNow, true, DateTimeOffset.UtcNow.AddDays(-1));
+
+    [Fact]
+    public async Task Handle_WhenUserHasAwaitingConfirmationSubscriptionRequest_SetsBillingPendingReview()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var request = PaymentRequest.Create(userId, PaymentPeriod.Quarter, 1000);
+        request.MarkPaymentSent();
+        dbContext.PaymentRequests.Add(request);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        _identityService
+            .ListUsersAsync(1, 20, null, Arg.Any<CancellationToken>())
+            .Returns(new PagedList<UserSummaryDto>([Summary(userId)], 1, 1, 20));
+
+        var handler = new ListUsersQueryHandler(_identityService, dbContext);
+
+        var result = await handler.Handle(new ListUsersQuery(1, 20, null), CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        Assert.True(result.Value.Items.Single().BillingPendingReview);
+    }
+
+    [Fact]
+    public async Task Handle_WhenNoPendingRequest_LeavesBillingPendingReviewFalse()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+
+        _identityService
+            .ListUsersAsync(1, 20, null, Arg.Any<CancellationToken>())
+            .Returns(new PagedList<UserSummaryDto>([Summary(userId)], 1, 1, 20));
+
+        var handler = new ListUsersQueryHandler(_identityService, dbContext);
+
+        var result = await handler.Handle(new ListUsersQuery(1, 20, null), CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        Assert.False(result.Value.Items.Single().BillingPendingReview);
+    }
+
+    [Fact]
+    public async Task Handle_WhenPendingRequestIsRoleChangeTopUp_LeavesBillingPendingReviewFalse()
+    {
+        // RoleChangeTopUp — доплата за смену роли, не подписка; не должна показывать пользователя
+        // как "оплата на проверке" в админке (см. CLAUDE.md про Kind).
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var request = PaymentRequest.CreateRoleChangeTopUp(userId, 500);
+        request.MarkPaymentSent();
+        dbContext.PaymentRequests.Add(request);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        _identityService
+            .ListUsersAsync(1, 20, null, Arg.Any<CancellationToken>())
+            .Returns(new PagedList<UserSummaryDto>([Summary(userId)], 1, 1, 20));
+
+        var handler = new ListUsersQueryHandler(_identityService, dbContext);
+
+        var result = await handler.Handle(new ListUsersQuery(1, 20, null), CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        Assert.False(result.Value.Items.Single().BillingPendingReview);
+    }
+}

backend/tests/PnvPanel.Application.Tests/Auth/RefreshCommandHandlerTests.cs

@@ -100,4 +100,41 @@ public class RefreshCommandHandlerTests
         Assert.False(result.IsSuccess);
         Assert.Equal(AuthErrors.InvalidRefreshToken, result.Error);
     }
+
+    [Fact]
+    public async Task Handle_WhenUserBlocked_ReturnsUserBlocked()
+    {
+        var userId = Guid.NewGuid();
+        var profile = new CurrentUserProfile(
+            userId,
+            "alice",
+            Guid.NewGuid(),
+            "user",
+            IsActivated: true,
+            IsBlocked: true,
+            MaxConfigs: 3,
+            MaxIpLimit: RoleQuota.Unlimited,
+            SubscriptionToken: "sub-token",
+            BillingEnabled: false,
+            BillingPaidUntil: null,
+            BillingSuspended: false
+        );
+        var rotated = new RotatedRefreshToken(
+            userId,
+            "new-refresh-token",
+            DateTimeOffset.UtcNow.AddDays(30)
+        );
+
+        _refreshTokenService
+            .RotateAsync("old-token", Arg.Any<CancellationToken>())
+            .Returns(Result.Success(rotated));
+        _identityService.GetProfileAsync(userId, Arg.Any<CancellationToken>()).Returns(profile);
+
+        var result = await CreateHandler()
+            .Handle(new RefreshCommand("old-token"), CancellationToken.None);
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(AuthErrors.UserBlocked, result.Error);
+        _jwtTokenService.DidNotReceive().GenerateAccessToken(Arg.Any<AuthenticatedUser>());
+    }
 }

backend/tests/PnvPanel.Application.Tests/Billing/CreatePaymentRequest/CreatePaymentRequestCommandHandlerTests.cs

@@ -150,6 +150,9 @@ public class CreatePaymentRequestCommandHandlerTests
     {
         using var dbContext = InMemoryDbContextFactory.Create();
         var userId = Guid.NewGuid();
+        var pricing = PricingSettings.CreateDefault();
+        pricing.Update(500, 450, 400);
+        dbContext.PricingSettings.Add(pricing);
         dbContext.PaymentRequests.Add(PaymentRequest.Create(userId, PaymentPeriod.Quarter, 1000));
         await dbContext.SaveChangesAsync(CancellationToken.None);
 

backend/tests/PnvPanel.Application.Tests/Billing/MarkPaymentSent/MarkPaymentSentCommandHandlerTests.cs

@@ -16,13 +16,14 @@ public class MarkPaymentSentCommandHandlerTests
 {
     private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();
     private readonly IXuiPanelGateway _gateway = Substitute.For<IXuiPanelGateway>();
+    private readonly IRealtimeNotifier _notifier = Substitute.For<IRealtimeNotifier>();
     private readonly ITelegramNotifier _telegramNotifier = Substitute.For<ITelegramNotifier>();
     private readonly ILogger<MarkPaymentSentCommandHandler> _logger = Substitute.For<
         ILogger<MarkPaymentSentCommandHandler>
     >();
 
     private MarkPaymentSentCommandHandler CreateHandler(IAppDbContext dbContext, Guid userId) =>
-        new(dbContext, _identityService, _gateway, _telegramNotifier, FakeCurrentUser.Authenticated(userId, "alice"), _logger);
+        new(dbContext, _identityService, _gateway, _notifier, _telegramNotifier, FakeCurrentUser.Authenticated(userId, "alice"), _logger);
 
     private static CurrentUserProfile Profile(Guid userId, DateTimeOffset? paidUntil) =>
         new(
@@ -139,6 +140,7 @@ public class MarkPaymentSentCommandHandlerTests
                 Arg.Is<DateTimeOffset?>(d => d > DateTimeOffset.UtcNow),
                 Arg.Any<CancellationToken>()
             );
+        await _notifier.Received(1).NotifyBillingStatusChangedAsync(userId, Arg.Any<CancellationToken>());
     }
 
     [Fact]

backend/tests/PnvPanel.Application.Tests/Configs/Rotate/RotateVpnConfigCommandHandlerTests.cs

@@ -1,3 +1,5 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
 using NSubstitute;
 using PnvPanel.Application.Auth;
 using PnvPanel.Application.Common.Interfaces;
@@ -5,13 +7,53 @@ using PnvPanel.Application.Common.Models;
 using PnvPanel.Application.Configs;
 using PnvPanel.Application.Configs.Rotate;
 using PnvPanel.Application.Tests.TestSupport;
+using PnvPanel.Domain.Activation;
+using PnvPanel.Domain.Apps;
+using PnvPanel.Domain.Audit;
+using PnvPanel.Domain.Billing;
 using PnvPanel.Domain.Configs;
 using PnvPanel.Domain.Inbounds;
+using PnvPanel.Domain.Instructions;
+using PnvPanel.Domain.News;
 using PnvPanel.Domain.Nodes;
+using PnvPanel.Domain.Pricing;
+using PnvPanel.Domain.Support;
+using PnvPanel.Domain.Telegram;
+using PnvPanel.Infrastructure.Persistence;
 using Xunit;
 
 namespace PnvPanel.Application.Tests.Configs.Rotate;
 
+/// <summary>Оборачивает реальный AppDbContext, но всегда фейлит SaveChangesAsync — симулирует сбой БД
+/// после успешного создания клиента в панели (DbUpdateException — единственный тип, который ловит
+/// RotateVpnConfigCommandHandler для компенсирующего отката).</summary>
+public sealed class ThrowingSaveDbContext(AppDbContext inner) : IAppDbContext
+{
+    public DbSet<ActivationRequest> ActivationRequests => inner.ActivationRequests;
+    public DbSet<AuditLog> AuditLogs => inner.AuditLogs;
+    public DbSet<TelegramLinkToken> TelegramLinkTokens => inner.TelegramLinkTokens;
+    public DbSet<TelegramLoginRequest> TelegramLoginRequests => inner.TelegramLoginRequests;
+    public DbSet<Node> Nodes => inner.Nodes;
+    public DbSet<Inbound> Inbounds => inner.Inbounds;
+    public DbSet<VpnConfig> VpnConfigs => inner.VpnConfigs;
+    public DbSet<TrafficSample> TrafficSamples => inner.TrafficSamples;
+    public DbSet<ClientApp> ClientApps => inner.ClientApps;
+    public DbSet<NewsPost> NewsPosts => inner.NewsPosts;
+    public DbSet<SupportTicket> SupportTickets => inner.SupportTickets;
+    public DbSet<TicketComment> TicketComments => inner.TicketComments;
+    public DbSet<TicketAttachment> TicketAttachments => inner.TicketAttachments;
+    public DbSet<InstructionIntro> InstructionIntros => inner.InstructionIntros;
+    public DbSet<InstructionTab> InstructionTabs => inner.InstructionTabs;
+    public DbSet<PricingSettings> PricingSettings => inner.PricingSettings;
+    public DbSet<PricingDiscountTier> PricingDiscountTiers => inner.PricingDiscountTiers;
+    public DbSet<BillingSettings> BillingSettings => inner.BillingSettings;
+    public DbSet<PaymentRequest> PaymentRequests => inner.PaymentRequests;
+    public DatabaseFacade Database => inner.Database;
+
+    public Task<int> SaveChangesAsync(CancellationToken cancellationToken) =>
+        throw new DbUpdateException("simulated failure");
+}
+
 public class RotateVpnConfigCommandHandlerTests
 {
     private readonly IXuiPanelGateway _gateway = Substitute.For<IXuiPanelGateway>();
@@ -231,4 +273,76 @@ public class RotateVpnConfigCommandHandlerTests
         Assert.Equal(gatewayError, result.Error);
         Assert.Equal("old-external-id", config.ClientExternalId);
     }
+
+    [Fact]
+    public async Task Handle_WhenSaveChangesFailsAfterAddClient_RemovesOrphanedClientAndReturnsRotateFailed()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        _identityService
+            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
+            .Returns(MakeProfile(userId));
+
+        var node = Node.Register(
+            "node-1",
+            new Uri("https://node1.example.com"),
+            new NodeCredentials("admin", "protected"),
+            null
+        );
+        var inbound = Inbound.FromRemote(node.Id, "1", VpnProtocol.Vless, "remark", 443);
+        var config = VpnConfig.Create(userId, inbound.Id, VpnProtocol.Vless, null);
+        config.AssignRemoteClient("old-external-id");
+
+        dbContext.Nodes.Add(node);
+        dbContext.Inbounds.Add(inbound);
+        dbContext.VpnConfigs.Add(config);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        _gateway
+            .AddClientAsync(
+                Arg.Any<Node>(),
+                inbound.RemoteInboundId,
+                config.Protocol,
+                Arg.Any<string>(),
+                Arg.Any<string>(),
+                Arg.Any<int>(),
+                Arg.Any<DateTimeOffset?>(),
+                Arg.Any<CancellationToken>()
+            )
+            .Returns(Result.Success("new-external-id"));
+
+        var handler = new RotateVpnConfigCommandHandler(
+            new ThrowingSaveDbContext(dbContext),
+            _gateway,
+            _identityService,
+            FakeCurrentUser.Authenticated(userId)
+        );
+
+        var result = await handler.Handle(
+            new RotateVpnConfigCommand(config.Id),
+            CancellationToken.None
+        );
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(ConfigErrors.RotateFailed, result.Error);
+        // Осиротевший клиент, успевший создаться в панели до сбоя SaveChanges, откатывается.
+        await _gateway
+            .Received(1)
+            .RemoveClientAsync(
+                Arg.Any<Node>(),
+                inbound.RemoteInboundId,
+                "new-external-id",
+                config.Protocol,
+                Arg.Any<CancellationToken>()
+            );
+        await _gateway
+            .DidNotReceive()
+            .RemoveClientAsync(
+                Arg.Any<Node>(),
+                inbound.RemoteInboundId,
+                "old-external-id",
+                config.Protocol,
+                Arg.Any<CancellationToken>()
+            );
+    }
 }

backend/tests/PnvPanel.Application.Tests/Support/ReopenTicketCommandHandlerTests.cs

@@ -83,4 +83,29 @@ public class ReopenTicketCommandHandlerTests
         Assert.False(result.IsSuccess);
         Assert.Equal(SupportErrors.NotFound, result.Error);
     }
+
+    [Fact]
+    public async Task Handle_WhenRoleRequestResolved_ReturnsOnlyBugReportCanBeReopened()
+    {
+        // approve/reject — единственный способ решить заявку на роль/продление (см. CLAUDE.md);
+        // Reopen для них запрещён даже если тикет каким-то образом оказался Resolved.
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var ticket = SupportTicket.CreateRoleRequestForExistingRole(userId, Guid.NewGuid());
+        ticket.Resolve();
+        dbContext.SupportTickets.Add(ticket);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        var currentUser = FakeCurrentUser.Authenticated(userId);
+        var handler = new ReopenTicketCommandHandler(dbContext, _telegramNotifier, currentUser);
+
+        var result = await handler.Handle(
+            new ReopenTicketCommand(ticket.Id),
+            CancellationToken.None
+        );
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(SupportErrors.OnlyBugReportCanBeReopened, result.Error);
+        Assert.Equal(TicketStatus.Resolved, ticket.Status);
+    }
 }

backend/tests/PnvPanel.Application.Tests/Telegram/GetLoginRequestStatusQueryHandlerTests.cs

@@ -150,4 +150,74 @@ public class GetLoginRequestStatusQueryHandlerTests
         Assert.False(result.IsSuccess);
         Assert.Equal(AuthErrors.Unauthorized, result.Error);
     }
+
+    [Fact]
+    public async Task Handle_WhenApprovedAndUserBlocked_ReturnsUserBlockedWithoutIssuingTokens()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var request = TelegramLoginRequest.Create(TimeSpan.FromMinutes(5), null);
+        request.Approve(userId);
+        dbContext.TelegramLoginRequests.Add(request);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        var profile = new CurrentUserProfile(
+            userId,
+            "alice",
+            Guid.NewGuid(),
+            "user",
+            true,
+            true,
+            3,
+            RoleQuota.Unlimited,
+            "sub-token",
+            false,
+            null,
+            false
+        );
+        _identityService.GetProfileAsync(userId, Arg.Any<CancellationToken>()).Returns(profile);
+
+        var handler = CreateHandler(dbContext);
+
+        var result = await handler.Handle(
+            new TelegramNs.GetLoginRequestStatusQuery(request.Id),
+            CancellationToken.None
+        );
+
+        Assert.False(result.IsSuccess);
+        Assert.Equal(AuthErrors.UserBlocked, result.Error);
+        // Уже потреблён предыдущим прогоном лока — токены выпустить не успели, но повторно claim'ить нельзя.
+        Assert.Equal(TelegramLoginStatus.Consumed, request.Status);
+        await _refreshTokenService
+            .DidNotReceive()
+            .IssueAsync(Arg.Any<Guid>(), Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task Handle_WhenAlreadyConsumedByAnotherPoll_ReturnsConsumedWithoutTokens()
+    {
+        // Второй поллер той же вкладки после того, как первый уже забрал вход (Consume()) —
+        // короткий путь ДО AdvisoryLock (status != Approved), токены повторно не выпускаются.
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var userId = Guid.NewGuid();
+        var request = TelegramLoginRequest.Create(TimeSpan.FromMinutes(5), null);
+        request.Approve(userId);
+        request.Consume();
+        dbContext.TelegramLoginRequests.Add(request);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        var handler = CreateHandler(dbContext);
+
+        var result = await handler.Handle(
+            new TelegramNs.GetLoginRequestStatusQuery(request.Id),
+            CancellationToken.None
+        );
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal(TelegramLoginStatus.Consumed, result.Value.Status);
+        Assert.Null(result.Value.Auth);
+        await _refreshTokenService
+            .DidNotReceive()
+            .IssueAsync(Arg.Any<Guid>(), Arg.Any<CancellationToken>());
+    }
 }